Suppose I have 100 balls in a box and 10 of them are red. If I randomly take out 40 of them, what is the probability that I can get at least 6 red balls? How is this worked out?
Use Hypergeometric Probability.
You may use Excel Formula for this and work it out as:
=HYPGEOMDIST(6,40,10,100)
Which works out to 10%
This is the probability of exactly 6 red balls. To find the probability of at least 6 red balls, you also need to calculate the probabilities of 7, 8, 9, and 10 balls as well and then sum them all. Using Stata, I make it to be 15.4%.
I agree with Kieran Mccaul....if ur sampling scheme is without replacement then the distribution is Hypergeometric and if with replacement, it is binomial distribution....and the above probality is...P(X>=6)= 1-F(5)
This is a Hypergeometric Distribution if you are drawing all the balls at a time. To compute this numerically we have: x={1-P(no. of red balls
- Badges
- Science topic
- Similar topics
- Mathematics
- Statistics